Oils for two-cycle engines containing basic amino-containing detergents and aryl halides



United States Patent No Drawing. Filed Sept. 8, 1964, Ser. No. 395,032 9 Claims. (Cl. 252-515) This invention concerns lubricating oils useful primarily in two-cycle engines. More particularly, this invention concerns lubricating oils containing aryl halides and amino-containing lubricating oil detergents,

Since the advent of the second World War, the use of the two-cycle engine has proliferated. With the increase in the numbers of motorcycles, motorscooters, chainsaws, lawnmowers, and outboard engines for recreation and commercial boating, the two-cycle engine has secured a place as a prime power source. Despite the popularity and wide distribution of the two-cycle engine, no effort has been made on a broad commercial scale to provide a gasoline tailored to the two-cycle engines needs. Rather, the efforts of the industry have been directed toward providing an oil which, when combined with gasoline used for automobiles, would be adapted to the requisites of the two-cycle engine.

The presence of the oil admixed with the gasoline increases the tendency for deposits to collect in the exhaust port and piston crown. The presence of the lead compounds which are usually present in gasoline, leads to spark plug fouling, particularly electrode bridging. Additives are therefore included in the oil to minimize the problems of deposits and spark plug fouling. It is essential that the additives do not interfere with each others respective functions. That is, the various additives in the oil must not react or interact with each other, so as to reduce their effectiveness or deleteriously affect the oils properties.

Pursuant to this invention, lubricating oil compositions are provided which are stable for long periods of time and minimize formation of deposits and spark plug fouling, which have an amino-containing amide or imide as the lubricating oil detergent, and an aryl halide as the scavenger.

The amount of halohydrocarbon used in the lubricating oil composition will vary with the particular halohydrocarbon used, the desired degree of performance, the particular fuel with which the lubricating composition is to be mixed, and the proportion in which the fuel and lubricating oil composition is mixed. Preferably, the amount of aryl halide used is such that the final fuel/ lubricating mixture will contain between about 2 to theories, more preferably between about 2.5 to 4 theories of halide. Generally, the amount of aryl halide in a lubricating oil composition will be between about 0.1 and 5 weight percent, preferably between 0.5 and 3 weight percent.

When the lubricating oil composition is added to a conventional leaded gasoline, it increases the theories of halide available in the gasoline. All conventional leaded gasolines already contain in addition to the alkyl lead compound, some organohalide to act as a scavenger for the lead. Commonly, about 1 to 1.5 theories of halide are present in such gasolines. While this amount of halide scavenger is about sufficient to deal With deposit problems in a 4-stroke internal combustion engine, it is not adequate in a 2-stroke engine, which is run on a mixture of fuel and lubricant. The effect of incorporating the lubricating oil composition to this invention in fuels for 2-stroke engines is to enhance the available theories of halide, thus minimizing the deposit problem, particularly with spark plugs.

The term theory is used in the industry to mean the quantity of organohalide required in the fuel or fuel/ lubricant mixture to convert (theoretically) all the lead present as tetraalkyl lead into a corresponding lead halide. Although tetraethyl lead is the most popular tetraalkyl lead used, the present compositions may be used with any fuel mixture which contains any of the commonly used tetraalkyl lead compounds, e.g., tetramethyl lead,

methyltriethyl lead, etc. While the fuel/lubricant mixtures may contain from about 0.1 to 5 cc./gal. of the tetraalkyl lead, the usual amount of tetraalkyl lead will be in the range from about 1 to 3 cc./gal., and more usually about 1.5 cc./ gal.

The amount of the amine detergent which is used in the base oil will be from about 0.5 weight percent to about 10 weight percent, more usually about 2 to 7 weight percent.

The aryl halides used in this invention are those from about 6 to about 16 carbon atoms, preferably 6 to 12 carbon atoms, having from one to two aromatic rings, either fused or nonfused. Each ring may have from about 1 to 3 halogen substituents of atomic number 17 to 35, i.e., chlorine and bromine; preferably, the aromatic molecule will have a total of from 1 to 4 halogens, particularly preferred, 2 halogens. The aromatic ring may be substituted with lower alkyl groups, i.e., alkyl groups of from 1 to 6 carbon atoms.

Illustrative compounds within the above description are chlorobenzene, bromobenzene, o-, m-, p-chlorotoluene, o-, 'm-, p-bromotoluene, 2-chloro-l,3-xylene, 4-chloro-l,3-xylene, 2-bromo-l,3-xylene, 4-bromo-1,3-xylene, 4,6-dichloro-1,3-xylene, 4,6-dibromo-l,3-xylene, 2,5-dibromo-l,4-Xylene, 2,5-dichloro-1,4-xylene, 2-bromo-5- chloro-l,4-xylene, 1,2-dibrom0benzene, 1,2-dichloroben- Zene, 1,4-dibromobenzene, 1,4-dichlorobenzene, l-bromo- 4-chlorobenzene, 2,4-dibromocumene, 4,4'-dibromobiphenyl, etc.

Also included in the lubricating oil is the carboxamide or imide of a polyamine. These lubricating oil detergents are reported in a number of domestic and foreign patents, e.g., US. Patents Nos. 2,922,708, 3,018,291, 3,- 024,237, 3,110,673, and French Patent No. 1,265,086. The polyamine will have from 2 to 6 amino groups and a molecular weight in the range from about 60 to about 600, preferably to about 300. The polyamine may be aliphatic, alicyclic, aromatic or combinations thereof, preferably aliphatic or heterocyclic, with one or more nitrogens present as annular members in the rings,e.g., piperazine. At least two of the amino groups in the polyamine prior to reaction with the carboxylic acids will have at least one hydrogen; that is, at least two of the amino groups will be either primary or secondary amines, preferably primary amines.

A preferred group of amines are the polyalkylene polyamines, having the following formula:

H m Z] n 2 wherein m is an integer of from 1 to 5 and n is an integer of from 1 to 6.

Illustrative of amines which are within the scope of this invention are diethylene triamine, triethylene tetramine, tetraethylene pentamine, trimethylene diamine, di- (hexamethylene)triamine, 2,4,2,4 tetraaminobiphenyl, 1,3,5 -triaminobenzene, 1,4-di aminomethyl cyclohexane, N,N-bis- [N- (Z-aminoethyl piperazino methane, etc.

The carboxylic acids which are reacted or contacted with the polyamines may be monoor dicarboxylic acids, i.e., of from 1 to 2 carboxyl groups. The acids will have an equivalent weight in the range of about to 1500, more usually to 1000. The carboxylic acids may have one or more sites of olefinic unsaturation. The carboxylic acid may be aliphatic, alicyclic, aromatic and combinations thereof, but are preferably aliphatic. Depending on the structure of the particular acids and amines used in the reaction, amides, imides or imidazolines may be formed.

The preferred monocarboxylic acids will generally be of from 5 to 30 carbon atoms, preferably from 12 to 20 carbon atoms. Such acids are exemplified by caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, linoleic acid, abietic acid, etc.

The preferred dicarboxylic acids are the alkenyl succinic acids. Usually, they are used in the reaction as anhydrides, i.e., alkenyl succinic anhydrides, having the following formula:

wherein R is an allrenyl group most conveniently obtained by polymerizing an olefin having from about 2 to carbon atoms. The molecular weight of the resulting polymer would generally be in the range of about 400 to 3000, more usually in the range of about 900 to 1200. Useful olefins are illustrated by ethylene, propylene, 1- butene, Z-butene, isobutene, l-pentene, and mixtures thereof, preferably isobutene. The methods of polymerizing such olefins to the polymers of the designated molecular weight are well known in the art and do not require exemplification here. As for preparing the alkenyl succinic anhydrides by reaction of the polyolefin and maleic anhydride, this reaction has been repeatedly published in numerous patents, e.g., US. Patents Nos. 3,018,250 and 3,024,195.

When referring to carboxylic acids, it is intended to include carboxylic acids and derivatives which will react with amines to form amides, imides or imidazolines. These acyl derivatives include acyl halides, carboxylic acids, anhydrides and esters. The preferred carboxylic acid derivatives are the carboxylic acid itself and the anhydride. However, in particular instances, the other derivatives may find use. The esters which find use are lower alkyl esters, e.g., methyl, ethyl and propyl.

Depending upon the particular carboxyl or acyl derivative used in the reaction with the polyamine, the tem perature will range from about 200 F. to about 500 F., more usually from about 275 to 450 F. The pressure used in the system will generally be atmospheric, although in specific instances higher or lower pressures may be used.

The carboxyl equivalents will be at least one fewer than the number of available primary and secondary amino groups. That is, if X is the number of available amino groups, i.e., primary and secondary, then at least one mole and not more than X-1 mole of carboxylic acidparticularly monocarboxylic acid-will be used per mole of polyamines. The equivalent ratio between carboxyl groups and available amino groups will generally be in the range of about .16 to .8 carboxyl equivalent per available amino group.

When the lubricating oil detergent is a polyamide of the alkylene polyamine:

wherein m and n are as defined previously, R is a carboxyl group of from 5 to 30 carbon atoms, and p is an I urnni umm where m, n and R are as defined previously. Preferred It varies from 2 to 5, particularly preferred is 11 equal to 4.

The formation of the amide or imide may be run in the presence or absence of an inert solvent. Inert solvents or dispersants include aromatic hydrocarbons, aliphatic hydrocarbons, specifically mineral oils of lubricating viscosity, aryl halohydrocarbons, ethers and polyethers, etc.

The reaction time will usually be in excess of two hours and rarely exceed 24 hours. More usually, the reaction time will be in the range of about 3 to 15 hours.

The reaction is usually carried out in an inert atmosphere, such as nitrogen, helium, argon, etc., that is in the absence of oxygen. During the reaction it is generally desirable to distill off the water or alcohol (when using an ester) as it is formed. This can be conveniently done by means of a Dean-Stark trap. Desirably, the pressure of the system may be reduced below atmospheric to facilitate the removal of the water.

The amine lubricating oil detergent and aryl halide may be combined with a variety of lubricating oils. Illustrative lubricating oils are petroleum derived oils or mineral oil, such as naphthenic base, paraffin base and mixed base lubricating oils; synthetic oils, e.g., alkylene polymers (such as polymers of butylene, l-decene, etc.), polyesters, etc.

The following examples are offered by way of illustration and not by way of limitation.

Example I equivalent weight of 310. The temperature was then raised to 298300 F. for a period in excess of one hour, followed by a further increase to 380 F., maintaining the temperature for a period of about 6 to 7 hours, while reducing the pressure to about 28 mm. Hg in order to facilitate the removal of water. At the end of this time, the reaction mixture is cooled, providing the desired basic amino-containing detergent.

Example 11 A mixture of 84 g. (0.45 mole) of tetraethylene pent amine and 702 g. (0.45 mole) of a polyisobutenyl succinic anhydride, wherein the polyisobuten yl radical was derived from a polyisobutene having a molecular weight of about 1000, was blended with agitation at F. in a nitrogen atmosphere. The temperature was increased to 400 F. over a period of one hour. Then the pressure was reduced to about 2 mm. Hg during a period of 30 minutes. The reaction mixture was allowed to reach room temperature while maintaining the reduced pressure. The reaction product contained about 3.8% nitrogen.

The reaction 'products from Examples I and II were mixed with aliphatic and aromatic halides, the mixture diluted with a mineral oil and maintained at the specified temperature, the basicity and viscosity being measured repeatedly. The following Table I indicates the results obtained:

6 The effect of aging on engine performance was also tested. Oil samples of a solvent refined paraffinic base oil containing weight percent of the detergent of Ex- TABLE I Base No. Viscosity at 100 F., SSU Composition 1 Ex. Scavenger 2 Wt. Percent Temp., (wt. percent) No. of Comp. F.

0 Day Days Days 40 Days 0 Day 20 Days 30 Days 40 Days Concentrates: 70

so I; 50 oil A 150 so I; 30.2 oil.--" B p-DBB 10.8 Z8

50 I; 41.4 oil 0 EDB 8. 6 70 5, 000

50 I; 43.1 oil 1) p-DCB e. 9 150 700 47 II; 49 oil E p-DBB 3.7 Z8

47 II; 49 oil F EDB 3.0 70

Finished Oils:

51; 95 oil G p-DCB 0.68

5 I; 95 oil H EDB 0.86 150 5 I; 95 oil I p-DBB 1.08 gg 319 5t; 95 oil J rig 5 r; 95 oil K o-DCB o. as Z8 1 Indicates wt. percent of product from Examples I and II mixed with a Mid-Continent 100 Neutral Oil.

2 p-D B B parardibromobenzene. p-D CB parardichlorobenzene. o-D CB =ortho-dichlorobenzene. E DB =ethylenedibromide. 1, 2, 4,-TCB=1, 2, 4,-triehlnrobenzene.

8 This base number is essentially that described in method ASTM D-664 except that a larger sample is used, in order to increase the accuracy of the titration.

16 days.

The aromatic halides were also tested in an engine. The test employs a model 850 Mercury outboard engine, 6-cylinder, 76 cubic inch, 85 H.P., running at 500 0 r.p.m. for 100 hours, wide open throttle. An engine is shut down only for spark plug replacement or mechancial trouble. It consists essentially of three 2-cylinde-r engines in one block equipped with three carburetors, so that three fuel/oil combinations can be run simultaneously.

The engine is mounted in a tank and is equipped With a special test wheel in place of a propeller. Cylinder head temperatures, water in and out temperatures, engine speed and fuel flow rate are recorded.

At the end of the test, inspections are made on the piston rings, piston ring grooves, land, skirt, head and underhead deposits, intake and exhaust port deposits and a land deposits, underhead deposit and exhaust port plugcylinder head deposits. Ring sticking is reported as F for free (no sticking) or the arc which is stuck (360 being totally stuck). Piston varnish is rated from 0-10, 10 being completely clean. The other deposits are reported on a rating of as being clean and 0 completely covered.

A Z-cycle engine motor oil was prepared by blending California base SAE 40 base oil containing 5 Weight percent of the reaction product of Example I, and 0.6 8 weight percent of p-dichlorobenzene. This amount of p-dichlorobenzene provided one additional theory of halogen for gasoline leaded to 1.5 cc. per gallon of tetraethyl lead and used at a fuel to oil ratio of 20: 1.

The gasoline with which the above-identified motor oil was blended in the fuel to oil ratio 20:1 had an ASTM D-86 distillation starting point of 95 F., a 50 percent point of 219 F. and an end point of 393 F. The gasoline contained 1.5 cc. of tetraethyl lead per gallon of gasoline and one theory of ethylene dibrornide scavenger.

The following Table II indicates the results obtained:

TABLE II Average Rating.--

ging. A rating of 050 is used with 50 as clean.

The following table indicates the results obtained:

TABLE III Weight per- Overall Scavenger cent in Oil 1 Engine 1 Rating Ethylene dibrornidc. 0.86 2 15.6 p-Dichlorobenzene. 0. 68 38. 5 p-Dibr01nobenzene 1. 1 37. 3

1 Equimolar amounts of the scavenger were used.

lhe engine was shut down after 6 hours because of excessive deposits.

It is evident that the aryl halides in combination with the polyamine detergents provide excellent results in the two-cycle engines. The engines are kept clean and the rings unstuck under extremely rigorous test conditions. Moreover, both the concentrates and the finished oil composition are stable for long periods of time, retaining their detergent and scavenger ability.

As will be evident to those skilled in the art, various modifications on this process can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

I claim:

1. A Z-cycle engine lubricating oil composition comprising:

a major proportion of an oil of lubricating viscosity,

from about 0.5 to about 10 Weight percent of a lubricating oil detergent having at least one free amino group and being the reaction product of a hydrocarbon polyamine of from 2 to 6 amino groups and a hydrocarbon carboxylic acid of from 1 to 2 carboxyl groups and of from 150 to 1500 equivalent weight, reacted at a temperature in the range of 200 to 500 F.,

and from about 0.1 to 5 weight percent of an aryl halide of from 6 to 10 carbon atoms, wherein the halogen of said halide is of atomic number 17 to 35.

2. A 2-cycle engine lubricating oil composition comprising:

a major proportion of an oil of lubricating viscosity;

from about 0.5 to 10 weight percent of a lubricating oil detergent of the following formula:

wherein m is an integer of from 1 to 5, n is an integer of from 1 to 6, p is an integer of from 1 to n and R is a hydrocarbon carboxacyl group of from 5 to 30 carbon atoms; and from 0.1 to 5 weight percent of an aryl halide of from 6 to 10 carbon atoms, wherein the halogen is of atomic number 17 to 35. 3. A composition according to claim 2 wherein n is 4, and p is an integer of from 2 to 3.

4. A composition according to claim 3 aryl halide is dichlorobenzene.

5. A composition according to claim 3 wherein said aryl halide is dibromobenzene.

6. A 2-cycle engine lubricating oil composition comprising:

a major proportion of an oil of lubricating viscosity; from about 0.5 to 10 Weight percent of a lubricating oil detergent of the following formula:

wherein said wherein m is an integer of from 1 to 5, n is an integer of from 1 to 6, and R is an alkenyl group having a molecular weight in the range from about 400 to 3000, and

from 0.1 to 5 weight percent of an aryl halide of from 6 to 10 carbon atoms, wherein the halogen is of atomic number 17 to 25.

7. A composition according to claim 6 wherein R is an alkenyl group of molecular weight in the range from about 900- to 1200.

8. A composition according to claim 7 wherein said aryl halide is dichlorobenzene.

9. A composition according to claim 7 wherein said aryl halide is dibromobenzene.

References Cited by the Examiner UNITED STATES PATENTS 3,083,162 3/1963 Lawrence 44-58 X 3,110,673 11/1963 Benoit 25251.5 3,192,910 7/1965 ColTield et a1 25251.5 X 3,216,936 11/1965 Le Suer 4458 X 3,219,666 11/1965 Norman et al. 25251.5 X

FOREIGN PATENTS 219,994 1/ 1958 Australia.

DANIEL E. WYMAN, Primary Examiner.

P. P. GARVIN, Assistant Examiner. 

1. A 2-CYCLE ENGINE LUBRICATING OIL COMPOSITION COMPRISING: A MAJOR PROPORTION OF AN OIL OF LUBRICATING VISCOSITY, FROM ABOUT 0.5 TO ABOUT 10 WEIGHT PERCENT OF A LUBRICATING OIL DETERGENT HAVING AT LEAST ONE FREE AMINO GROUP AND BEING THE REACTION PRODUCT OF A HYDROCARBON POLYAMINE OF FROM 2 TO 6 AMINO GROUPS AND A HYDROCARBON CARBOXYLIC ACID OF FROM 1 TO 2 CARBOXYL GROUPS AND OF FROM 150 TO 1500 EQUIVALENT WEIGHT, REACTED AT A TEMPERATURE IN THE RANGE OF 200* TO 500*F., AND FROM ABOUT 0.1 TO 5 WEIGHT PERCENT OF AN ARYL HALIDE OF FROM 6 TO 10 CARBON ATOMS, WHEREIN THE HALOGEN OF SAID HALIDE IS OF ATOMIC NUMBER 17 TO
 35. 